What does the OBD system monitor?

The On-Board Diagnostics (OBD) system is designed primarily to monitor vehicle performance and the functionality of emissions-related components. It plays a crucial role in ensuring that the vehicle meets environmental standards by checking various systems that control emissions. This includes the engine control unit, fuel injection system, catalytic converter, and other components that affect air quality and emissions output.

By continuously monitoring these components, the OBD system can detect malfunctions or inefficiencies that could lead to increased emissions or performance issues. When a problem is identified, the OBD system triggers a warning light on the dashboard and stores diagnostic trouble codes, which can be read with a scan tool. This allows for timely maintenance and repair, ensuring not only optimal vehicle performance but also compliance with emissions regulations.

In contrast, monitoring of vehicle weight and load capacity, brake fluid levels, and tire pressure involves different systems and does not pertain to the primary function of the OBD system, which focuses solely on diagnostics related to engine and emissions health.